Physicists have finally confirmed a phenomenon that sounds like pure science fiction: waves that appear to bounce off a sudden change in time rather than a surface in space. The effect, known as a ...

Physicists have demonstrated that waves can bounce off boundaries in time, not just in space, producing signals that behave as time-reversed copies of the original. These experiments, conducted in ...

Learn how cleaner wrasse used a mirror and even dropped food to test their reflections, a behavior linked mostly to mammals. A small reef fish may be doing something scientists once thought was ...